I had to do it 2 years ago or so because the SSL key became obsolete and it no longer worked. To reload your FRITZ!Box, you need to reboot the device. Here are the steps:

1. **Restart via the user interface:**
- Open a web browser and enter "fritz.box" in the address bar.
- Log in with your password.
- Go to "System" and then to "Backup".
- Click on "Restart" and confirm.

2 **Restart by disconnecting the power supply:**
- Unplug the FRITZ!Box from the mains.
- Wait about 10 seconds.
- Plug the power plug back in.

3 **Restart via the MyFRITZ!App:**
- Open the MyFRITZ! app on your smartphone.
- Log in and select your FRITZ!Box.
- Go to "Home network" and then to "FRITZ!Box restart".

After the restart, your FRITZ!Box should be fully functional again.

If you want to update the firmware, you can also do this via the user interface under "System" and "Update".

Thank you,
Simon